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(No Model.) 2 Sheets-Sheet 1.

E. THOMSON,

ELECTRIC ARC LAMP.

No. 274,413. Patented MaIuZO, 1883.

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(No Model.) 2 Sheets-Sheet 2.

E. THOMSON.

ELECTRIC ABC LAMP.

No. 274,413. Patented Mar.20,1883.

UNITED STATES PATENT OFFICE.

ELIHU THOMSON, OF NEYV BRITAIN, CONNECTICUT, ASSIGNOR TO THE AMERICAN ELECTRIC COMPANY, OF SAME PLACE.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 274,418, dated March 20, 1883.

Application filed January 52, 1883. (No model.)

To all whom it may concern Be it known that LELIHU THOMSON, a citizen ofthe United States, and a resident of New Britain, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Electric-Arc Lamps, of which the following is a specification.

My invention relates to the regulating or feed controlling mechanism of electric -'arc lamps; and its purpose is to secure the desired operation of lifting or separating the carbons to form the arc and of allowing the carbon or carbons tofeed to compensate for combustion without the employment of a system of main and derived circuit-coils 0r electro-magnets acting differentially or in opposition to one an other, as is ordinarily the case.

My invention is more especially adapted for use upon acircuitin which thecurrent strength is normally constant, or is maintained by suitable regulating appliances at a constant or nearly constant strength and its principle or mode of operation may be briefly stated to be as follows: I employ both main and derived circuit coils or magnets, but the direct and derived circuit currents circulating in said coils are both made, through ordinary or suitable devices, to act upon the feed-regulating mechanism in the same directions-that is, their combined effect is utilized instead of their differential effectas is ordinarily the case. This is accomplished by using both coils conjointly as exciters for a single electro-magnet or axial core, or by winding them separately and al-.

separation and feed of the carbons, suitable intermediate devices being used between the increased or strong pull due to the combined efl'ects of the direct and derived circuit-currents when along or lengthened arc exists. In the case of a lifting and releasing clutch,

Lamps constructed upon the above principle 4 are primarily intended for use on a circuit in which a nearly constant current is employed, as in that case the efi ect of the direct-circuit current is constant, thus allowing the feed to be accomplished solely by the variations in the derived-circuit current.

1n the accompanying drawings, Figure 1 is a side elevation of a lamp embodying my invention, and shows one method of applying the same to a lifting and releasing clutch. Fig. 2 illustrates a modified form of the invention. Figs. 3, 4, and 5illustrate the operation of the intermediate devices between the magnet system and the clutch. Fig. 6 shows a modification of the toggle-joint mechanism of Fig. 1. Fig. 7 is a top view of the clutch shown in Fig. 1. Fig.8 showshowacam may be used in place of the toggle-joint for reversing the movement of the clutch on a continued movement of the armature or aXial-corein one direction. Fig. 9 illustrates the application of the invention to-a gear-train lamp.

In Figs. 1, 2, and 6, H indicates the frame of the lamp supporting the various parts, and serving to guide the carbon holder or rod R, carrying the upper carbon, E. E indicates the lower or negative carbon. M and N are respectively the magnet-coils in the main or principal circuit, and in a derived circuit around the arc, which coils are, in the present instance, made to act on axial cores D S, connected by a cross-piece. A clamping and lifting clutch, O, engages with the carbon-carrier, and is constructed substantially in the manner described in prior applications for patents filed by me.

It consists of a perforated clamp-body, 3. and a hinged toe or cam, 2, held against the carbon rod by a spring, so as to prevent the rod from moving whenever the clamp-body is lifted, and disengaged from the rod by a stop, 5, when the clamp is lowered. The body of the clutch G is pivoted to a knee or toggle joint, on a, the lower end of which is upheld by or pivoted to a fixed support, It. Suitable connections from the knee-joint to the axial magnets D and S are provided,consisting of a link, l, elbow-lever L, and link T, or other devices adapted to communicate the movement of the axial cores to the knee-joint, so that when said magnets act by the passage of current their cores or armatures shall impart a horizontal thrust against the knee or toggle joint, so as to first straighten it and afterward bend it on the other side. These three positions assumed by the knee-joint in lifting and lowering the clamp are shown in Figs. 3. 4, and 5. During the passage from position Fig. 3 to that of Fig. 4, the clutch (l is lifted and the carbon rod in turn lifted, and an arc is formed between the carbons; but during the passage from position Fig. 4 to position Fig. 5 the clutch is lowered and finally released, so as to feed the carbons. The adjustment of the strengths of the magnets D and S is made so that on first passing current through the lamp, and before any consumption of carbons has taken place, the parts shall take the positions Fig. a-that is, the clutch will be at its highest position. Now, as the are E E lengthens by consumption of carbons, thei'orce of the shunt-magnet S increases, and finally brings the parts into position 5, where a feed of the carbon takes place, from which time the feeding is repeated at intervals more or less regular, depending on the perfection of the mechanism.

Fig. 2 shows a modification in which the electro-magnets or coils M N are placed horizontally one above the other, and each provided with a fixed core having a tapered pole acting in conjunction with a perforated armature, as described in United States Patent No. 253,958, so as to admit long range of movement, and uniformity of attraction in various positions. They both attract their armatures in the same direction and against a retractile spring, Z, which need not be used with the arrangement shown in Fig. 1, because in the latter arrangement the weight of the cores D and S is sufficient for certain retraction. The general operation is substantially the same as with the arrangement shown in Fig. 1.

Fig. 6 shows a modification of Fig. 1, giving similar effects. The upwardly-actin g axial magnets D and S are pivoted respectively to the ends of a bar, r, to which latter, near its central portion, is connected the lever L. The part a of the knee or toggle joint is removed, and the link Z instead prolonged, so as to rest on a roller-support, W, to diminish friction. The effects are nearly the same as in Fig. 1, already described, except that the magnets do not necessarily move together. Gore D is first to move, and brings link m into vertical position, after which core S, which is lifted when the arc lengthens by consumption of the carbon, carries link m to the right beyond the vertical, and so lowers and releases the clamp. In this case it is evident that the weight of the core S must be sufficiently great to prevent it from being moved during formation of the arc by the lifting of D. The sequence of actions and independent connection of magnets with a feed and lifting clamp (shown in this figure) forms the subject of another application for patent filed by me, and no special claim is therefore herein made to it;

It is obvious that many other devices might be used in place of the toggle-joint for reversing the movement of the clamp-body after a certain point in the continued movement of the core or armature.

Fig. 8 shows how a cam having a double incline may be used for the purpose. A indicates the cam, which travels beneath the clamp 0 when the lever L is operated, first raising said clamp, and then, upon a continued movement of the lever, allowing the clamp to fall when the apex of the cam passes the frictionroller 12.

I do not limit myself so far as the intermediate device between the magnet system and the clamp or its equivalent is concerned, as any device may be used in this connection which will first serve to lift the clamp, and then, upon a continuance of the movement of the primary actuating device, will cause a return or backward movement. Nor do I limit myself to the form of clutch herein shown, since any other may be used in its place.

In Fig. 9 the manner of applying the invention to one form of a gear train-lamp is illustrated. B indicates the usual lever in which the retarding train-gearing, with the carboncarrier, is mounted, and F the pinion engaging with the rack on the carrier. The vibrating fiy of the escapement is indicated at 15, while 16 indicates the stationary detenttherefor. The operation of such a lamp is Well known in the art. The end of the lever at which the carrier is placed is lifted to form the arc, while a reverse movement sufficient to dis engage the fly will allow the carbon to feed. In this, as in the preceding figures, L indicates the operating-lever actuated by the magnet system, and connected with the leverB through the toggle-joint or its equivalent, so that the first movement of the lever L will raise lever B from the arc, and upon a continuance of said movement in the same direction the lever B will be lowered, so as to disengage the detent and allow the train to revolve and the carbon to feed. The application to other forms of lamp will be obvious. In any case it is only necessary to connect the toggle-joint or its equivalent to that part of the lamp by whose reciprocating movement the separation and the feed of the carbons will be allowed or effected.

The main-circuit magnet may be placed at any desired point of the direct circuit, and in some cases it may be desirable to place it outside of the branch between the points X and Y, instead of in said branch, since in that case its strength would be less liable to be alfected by fluctuations in the length of arc. The coils N may be in the derived circuit itself, or may be controlled indirectly by a coil in said derived circuit, after the manner described in Patent No. 258,684, or in any other suitable manner.

What I claim as my invention is- 1. The combination, with the device controlling the separation and feed of the carbons in an electric lamp, of main and derived circuit coils or helices acting in conjunction to impart movement to a core or armature in the same direction, and intermediate mechanism between the core or armature and said controlling device for imparting movement thereto in one direction upon a moderate pull of the core or arm atn re. and a reverse or return movement of said device upon a stronger pull and continued movement of said core or armature.

2. The combination, with a carbon-carrier, of mechanism for lifting and controlling the feed of the same, main and derived circuit coils re-enforcing one another directly or indirectly in their pull upon a core or armature, and intermediate mechanism for reversing the movement of the lifting and controlling mechanism when said core or armature has passed a certain point in its movement under the influence of the derived-circuit coil.

The combination, with a lifting and releasing clutch, of main and derived circuit coils re-enforcing one another in their action upon the clutch, and intermediate reversing mechanism for causing the release of the clutch upon an increased pull due to an increased flow of current in the derived-circuit coil.

4. In an electrielamp, two solenoids or electro-magnets acting conjointly upon one or more cores or armatures, in combination with a clutch and suitable intermediate mechanism for first raising and locking said clutch upon the carrier, and afterward lowering and releasing the same upon a continued movement of the core or armature in the same direction.

5. The combination of acarbon-carrier,rnain and derived circuit coils, a lifting-clutch for separating the carbons by the combined and conjoint action of the direct and derived circuit coils, and means for causing the release of said carbon upon an increased action of the derived-circuit coil.

6. The combination, in an electric lamp, of a clutch, a toggle or knee joint, one or more cores or armatures connected directly or indirectly with said knee-joint, and main and derived circuit helices acting directly or indirectly but conjointly upon said cores or armatures.

7. The combination of the toggle or knee 'm n, or its equivalent, with the separating and feeding mechanism for the carbon, and two electro-magnets or solenoids exerting attractive forces in the same direction to actuate said knee or toggle joint, whereby said separating and feeding mechanism is made to adjust the carbon.

Signed at New Britain, in the county of Hartford and State of Connecticut, this 28th day of December, A. D. 1882.

ELIHU THOMSON.

Witnesses:

E. WILBUR Bron, W. O. WAKEFIELD. 

